1. Field of the Invention
The present invention relates to a shutter driving system for a camera. More particularly, the present invention relates to a shutter driving system for a digital camera, a camera device having the same, and a driving method thereof, which minimize a time lag and enable a compact design in structure by controlling shutter exposure time according to a predefined unit.
2. Description of the Related Art
Digital cameras of the related-art may have a Focal Plane Shutter (FPS) that includes an opening part of the shutter that should remain open so that an image of a subject can be shown through an Electronic View Finder (EVF) or a Liquid Crystal Display (LCD) installed at a backside of the camera. In such related-art digital cameras, a driving method of the camera may include providing components including a front-curtain and a rear-curtain in order to control opening and closing of the opening part, stopping a setting operation when in an open state of the opening part by driving only the rear-curtain after performing an exposure, and operating camera shutter devices to return to an exposure start position and moving a set member to an exposure completion position by operating the front-curtain to close the opening part as soon as the exposure is performed after operating the camera shutter devices for photographing. In such a driving method, the opening part for the exposure must go through an open state in a continuous photographing process, and after performing the exposure, a process of transferring data accumulated in an imaging device to a storage unit must be completed before the front-curtain and the rear-curtain move to the exposure start position.
Furthermore, a method of using a permanent magnet as a member for supporting and stopping a front-curtain and a rear-curtain has been suggested in the related-art. In the method using the permanent magnet, the rear-curtain stops at an exposure start position by using the permanent magnet after performing an exposure, and an opening part of a shutter remains in an open state while returning the front-curtain to an exposure completion position. When capturing a photograph, the opening part of the shutter is closed while moving the front-curtain to the exposure start position, and camera shutter devices move to the exposure completion position as soon as the exposure is performed. However, in this method, the rear-curtain is held for a long time by the permanent magnet, and thereby has a disadvantage that a deviation in timing of releasing the rear-curtain may be generated due to the operational characteristic of magnetic power of the permanent magnet. For that reason, operations of releasing the rear-curtain once before moving the front-curtain to the exposure start position and moving, again, the front-curtain and the rear-curtain to the exposure start position are needed. Accordingly, in the related-art capturing of a photograph, there is a problem that a long time lag is generated between the start of photographing by pressing a shutter release button and the start of an actual exposure in the related-art photographing.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.